u/Buttbadger

I (32F) am caught in a massive family blow-up with my older sister ("O", 40F), and I need an outside gut check because I'm honestly too close to it to tell if I'm being reasonable or just stubborn.

Some context first. O has spent my entire life trying to be a "third parent" to me. To be fair, our parents did put that pressure on her when we were kids, so I get where it started. But we are adults now, and I have told her flat out multiple times to just be my sister. She can’t do it. Any time I make a choice she doesn't like, she goes on a guilt-trip campaign. On top of that, she has literally leaked my private medical information to other people before without asking, so my trust in her is completely shot.

Lately, O has been completely spiraling, and a lot of it seems triggered by the fact that I bought my own house. Ever since I bought it, she’s been throwing massive tantrums, cursing our parents out, and blaming them for everything wrong in her life. She even went behind my back and called me a "trust fund baby" to our mom, which infuriates me because I work my ass off. The absolute kicker is that while our parents did help me with my down payment, I had to qualify for the mortgage entirely on my own, and they had explicitly given O the exact same financial offer in the past. She just never acted on it, and now she uses my housing milestone as an excuse to resent everyone and play the victim.

Historically, I’ve handled family drama by just trying to stay out of the blast radius, smoothing things over, staying neutral, and trying not to make things worse. But because of O's relentless hostility, she has basically cut our parents (73M, 64F) off almost completely at this point.

My parents aren't perfect. I experienced my own shit with them growing up. But our dad has Parkinson's disease now. Holding him accountable for things he did decades ago feels pointless because he literally doesn't remember them, and I've done the work to move past my issues with my mom. O hasn't gotten there, and that's her choice, but it results in a lot of hostility.

Because of that tension, my parents decided on their own to move closer to me. I didn't ask them to. They made that call because I'm the one who actually answers the phone and handles logistics or hospital visits without a massive emotional production.

I knew they were looking to move and had gone with my mom to look at a couple of places. I didn't tell O. Part of it was respecting my parents' privacy, but if I'm being totally honest, part of it was just selfish. I knew exactly what would happen if I did, and I didn't want the headache. My mom has also been incredibly flaky about this whole thing for months, so half the time I genuinely thought this was just another "wouldn't it be cool if we moved" conversation that wasn't going anywhere. I didn't realize she was serious until the offer actually went in.

Crucially, my mom did reach out to her directly to tell her she was selling the house and to come get any of her old stuff she wanted to keep. So O wasn't completely blindsided; she knew a move was happening.

Yesterday, O texted me because she found out my mom put an offer on a condo near me. I answered her questions normally about the area. Then later that night, she flipped the script and got aggressive. She said she was "surprised" I hadn't given her a "peep" about this when she visited me less than a week ago, acting like I sat across from her actively hiding a done deal. In reality, when I saw her, nothing was finalized and there wasn't even an offer on the table yet.

I told her flat out that I don't share other people's private information, and that I'm not a funnel for family gossip. O rejected that, claiming she "didn't want to feel isolated dealing with our parents getting older," and that I owed her this information. She started listing past medical events like she was building a case against me, mentioning a hospitalization and a 911 call (which was literally just our dad accidentally triggering his Apple Watch and not knowing how to cancel it).

I held my position, and then O went for the jugular. She accused me of "playing hide and seek" with our elderly parents and threatened to hide her own health information from me as payback, which is fine, because I never asked for it anyway.

That was my breaking point. I was just tired of being her punching bag. I told her she has a therapist and should work it out with them, told her I wasn't going to be talked to disrespectfully, and blocked her number. Now she’s sending giant walls of text via email to keep the fight going.

I feel justified in refusing to let her micromanage me or my parents' privacy, but the family fallout is getting messy.

Why I might be the asshole: I did know they were looking at places and chose to say nothing. I can see how, from her perspective, it looks like I was deliberately keeping her out of the loop and feeding into her paranoia about being isolated, rather than just respecting my parents' privacy. There’s a valid argument that when you have an aging parent with a progressive illness, siblings need to maintain open communication for basic coordination, even if they don't get along. By shutting down and blocking her during a major family transition, I might just be being rigid, petty, and making the overall chaos worse for my parents.

AITA?